Editable fields in Share user profile for LDAP sync users

Users are synced from AD using LDAP. For some users that are considered external, the email field is blank in AD, thus also in Alfresco.Now my understanding is that any field thats coming from the sync is read-only in edit mode for Share user profile.

Is it possible to configure alfresco share so that this (email in this case) field opens up for edit?Will Alfresco ldap sync overwrite fields with blank if that is what is returned from AD?I guess what I want is: If ldap sync returns blank/null, do nothing with the field. If a value is returned, overwrite whats in the field.